lncRNA SNHG15靶向miR-153对乳腺癌细胞线粒体途径凋亡的影响

Effect of lncRNA SNHG15 targeting miR-153 on apoptotic of mitochondrial pathway in breast cancer cells

目的:探讨lncRNA SNHG15靶向miR-153对乳腺癌细胞增殖和凋亡的影响及其凋亡机制。方法:用实时荧光定量PCR(qPCR)检测乳腺癌细胞系MDA-MB-231、BT-549和MCF-7中SNHG15表达水平。将MDA-MB-231细胞分为对照(Ctrl)组、si-NC组、si-SNHG15组、si-SNHG15+anti-NC组及si-SNHG15+anti-miR-153组,用MTT法及流式细胞术分别检测细胞的增殖活力和凋亡率。用双荧光素酶报告基因实验验证SNHG15和miR-153的靶向关系。用线粒体膜电位荧光探针(JC-1)染色法检测细胞线粒体膜电位,用Western blotting检测线粒体途径凋亡相关蛋白Bcl-2、Bax、caspase3、cleaved caspase3(c-caspase3)和Cyt-C的表达水平。结果:SNHG15在3种乳腺癌细胞中的表达水平均明显高于人正常乳腺上皮细胞MCF10A(均P<0.01)。SNHG15与miR-153存在靶向关系。沉默SNHG15后,与对照组比较,si-SNHG15组MDA-MB-231细胞增殖活力明显降低、凋亡率升高、线粒体膜电位降低(均P<0.01);细胞中Bcl-2和caspase3表达降低,Bax、c-caspase3和Cyt-C表达升高(均P<0.01)。si-SNHG15与anti-miR-153共同转染MDA-MB-231细胞后,可减弱si-SNHG15对细胞增殖、凋亡、线粒体膜电位及Bcl-2、Bax、caspase3、c-caspase3和Cyt-C表达的影响(均P<0.01)。结论:lncRNA SNHG15可靶向调控miR-153诱导MDA-MB-231细胞凋亡,其机制可能与调控细胞线粒体途径凋亡有关。

Objective:To investigate the effect of lncRNA SNHG15 targeting miR-153 on cell viability and apoptosis of breast cancer cells and its apoptotic mechanism.Methods:The expression of SNHG15 in breast cancer cell lines(MDA-MB-231,BT-549 and MCF-7)were detected by Real-time fluorescent quantitative PCR(qPCR).MDA-MB-231 cells were divided into control(Ctrl)group,si-NC group,si-SNHG15 group,si-SNHG15+anti-NC group and si-SNHG15+anti-miR-153 group.Cell viability and apoptosis rate were detected by MTT and Flow cytometry,respectively.The targeting relationship between SNHG15 and miR-153 was verified by Dual luciferase report gene system.Mitochondrial membrane potential fluorescent probe(JC-1)staining method was used to detect cell mitochondrial membrane potential.The expressions of mitochondrial apoptosis-related proteins(Bcl-2,Bax,caspase3,cleaved caspase3[c-caspase3]and Cyt-C)were detected by Western blotting.Results:The expression of SNHG15 in breast cancer cells was significantly higher than that in human normal mammary epithelial MCF10A cells(P<0.01).There was a targeting relationship between SNHG15 and miR-153.Compared with the control group,the cell viability and mitochondrial membrane potential of MDA-MB-231 cells in si-SNHG15 group were decreased,while apoptosis rate was increased(all P<0.01);the expressions of Bcl-2 and caspase3 were decreased while expressions of Bax,c-caspase3 and Cyt-C were increased(all P<0.01).However,co-transfection of si-SNHG15 and anti-miR-153 significantly attenuated the effects of si-SNHG15 on cell viability,apoptosis,mitochondrial membrane potential and expressions of Bcl-2,Bax,caspase3,c-caspase3 and Cyt-C(all P<0.01).Conclusion:lncRNA SNHG15 can target miR-153 to induce apoptosis of MDA-MB-231 cells,and the mechanism may be related to the regulation of apoptosis of mitochondrial pathway.